Saturday, 12 April 2014

The Revox B77 Tape DeckProven Professional Design.Precision TransportProfessional recordists know that for long-term stability and performance successful tape transport design must begin with the chassis frame itself. No matter how smooth-running the motors and highly-refined the heads, since both are referenced to the recorder's frame, any long-or-short-term flexing or imprecise machining in the chassis will inevitably degrade performance. To achieve the required stability - at a weight compatible with home use - the Revox B77 uses a sturdy aluminium die-casting for the chassis, headblock, pinch roller and mechanism, and each mounting point is painstakingly machined for extraordinary tolerances. The Nextel-coated case around the transport provides a similarly sturdy layer of protection for the mechanism.Precision Three-Motors DriveStuder-Revox manufactures its own drive and winding motors so their characteristics can be optimized for recorder use. For example, when heavy reels must be started up from rest they must be fed initially with a higher starting voltage, which is gradually reduced via a triac circuit to normal running voltage. The entire operation must be entirely smooth or the tape could snarl or stretch. Studer motors and controls are one reason why our decks are so widely acknowledged to be the gentlest-handling you can own.The capstan motor employs a precision-machined set of teeth at the circumference of its motor. As the motor turns, these teeth create a series of pulses that are read by a tachometer head and whose rate is compared against the frequency of a stable internal oscillator. In this way, even very slightest speed variations are immediately detected through a fast-acting servo system. To reduce wow and flutter even further, the direct-drive capstan shaft is machined to an accuracy of one one-thousandth of a millimeter, is hard chrome-plated and is artificially aged during the manufacturing process to ensure long-term stability.Precision Heads and ElectronicsStuder tape heads - from 1 to 24 track models - are world-renowned and are designed and build in our own facilities. The head cores are made from a physically hard, magnetically soft metal allay called Revodur, which has nearly perfect electromagnetic qualities. Whether you purchase your B77 in a quarter- or half-track stereo format its heads will be built to the same standard of polish employed in our professional studio decks.The head nest of the B77 also contains space (1) for the inclusion of a fourth head, to be used for slide-projector synchronization or other audio-video control purposes, in addition to the regular erase, record play units. An infrared sensor within the head area (2) actuates automatic shut-off in the event of tape run-out or breakage.Three-Head Monitoring and Special EffectsBecause the record and playback heads of the B77 are individual, separate units, each can be optimized for its specific function. A narrow gap is employed for playback to extend the frequency response, while a wider gap is employed during recording to ensure full penetration of the oxide layer on the tape. Since the record and playback electronics are also separate, this permits you to monitor the recorded result a split-second later, making direct comparison possible to avoid the possibility of an unsatisfactory recording. The sophisticated electronics and separate heads of the B77 also permit various special recording effects. Without external components or cables the Revox B77 can:- Duoplay, where both recorded tracks are used simultaneously but for different, interspersed information, as in language laboratories.- Simuplay, where a running commentary musical part, or translation is recorded on one track and a synchronized musical part or other accompanying material is recorded on the other.- Sound-on-Sound, where a single individual, by playing various musical parts and successively mixing his live part with a previously recorded section, can build up an entire performance.- Echo/Reverb, where tape-delayed echo or ambience can be added to a recorded track.Precision Editing FacilitiesAn accurate splicing block and non-magnetic sheertype cutter are build right into the front panel of the B77, encouraging creative tape editing. Additionally, a lever switch is included that activates the playback amplifiers during the fast-winding modes, and shifts their operation to a pulse-type control. In this way you can quickly shuttle back and forth between fast forward and rewind to find the exact point at which an editing cut is to be made. For even finer-pin pointing of critical cuts the reels can be rotated manually while the tape remains against the playback head.Fine Speed AdjustmentThe Revox B77 MK II (not the MK I) contains a built-in vari-speed control with a range of ± 2 half-tones. for a larger range of ± 7 half-tones it is necessary to use the external vari-speed control.

Thursday, 10 April 2014

The 3 way speaker system by which the low magnetism leakage design was performed for the correspondence of audio-video age.

DRS (Dynamic Response Suspension) which induces the outstanding linearity is adopted as each unit.The permeability of air is high to a Woofer, the small double twill damper of mechanical resistance is adopted as it, the newly developed chemical edge is used for a mid range, and the nonlinearity of back pressure is decreased by the sound control inside a chamber.Moreover, the tweeter has changed the input signal into the air signal efficiently by the Mie suspension structure and a new model-like horn.

A 32cm cone type unit is adopted as low-pass.A full-range voice coil and a low range voice coil are prepared for a Woofer, only a super-low-pass signal is added to a low range voice coil, and the EBD (Electronic Bass Drive) scheme which has improved low-pass electrically is adopted as this unit.Moreover, a cut and the subpole of pole piece were installed in the magnetic circuit, the magnetic-flux distribution was made into the order symmetry, and LDMC (Linear Drive Magnetic Circuit) which eliminated the nonlinearity of the driving force by the swing of a voice coil is adopted. This is reducing the swing distortion to conventional 1 / 2 - 1/3.Furthermore, the highly precise technology is supplied over details, such as DRS and an intensity up of a frame.Moreover, leakage flux is reduced with the dual magnet scheme.

A 7.6cm dome shape unit is adopted as a mid range.The phi76mm beryllium mid range is adopted as a diaphragm.Furthermore, much new technology which prevents muddiness of sound, such as double dumping of an equalizer, is introduced.

The beryllium ribbon tweeter which Pioneer developed is adopted as a high region.Leakage flux was reduced with the magnetic shielding cap, and the influence on the Braun tube is prevented.

The network is carrying out thorough exclusion of the king falloff which repeats a study with circuitry, an element, and a layout.The balanced network circuitry (PAT.P) which prevents the leakage by a sorption and earth line of the counter-electromotive force of a Woofer is adopted. Moreover, the magnetic material leading to propagation distortion is eliminated until it results in a screw and a nut,The film capacitor in which ESR (equivalent series resistance) is lower than the conventional film a single figure is adopted as a capacitor, and thorough investigation of low-loss-izing, such as using the oxygen-free-high-conductivity-copper line of a very thick also for a choke coil and lead wire, and the low crosstalk is carried out.

The enclosure is also examined and designed from form and the quality of the material.The high-density needle-leaf tree particle board excellent in the acoustic feature was used for the front baffle, and diffraction phenomena are eliminated by the round baffle which gave R to the corner on either side.While this realizes the sound field of a natural spread, the transient of inside loud sound is improved greatly.Furthermore, a symmetrical unit design is taken in so that a clear image lateralization may be obtained, and it has become a real cabinet of the craft finish using ebony material.

Friday, 4 April 2014

The Marantz 4230 is created for stereo and 4 channel (Quadraphonic) sources. Marantz called the concept sonorous "Stereo 2 + Quadradial 4". Some quadro decoder systems are on board. For an optional SQ decoder, there is a recess in the base plate, it can simply docked.

The rated output of 2x40 watts or 4x17 watts was always outbid in tests thanks to the Marantz typical transformer dimension. For the good FM reception with the possibility of multipath signal evaluation is a high quality FM front end module responsible.

The versatile enabled receiver 4240 from the legendary first 70 series is true fun and gives an entirely sophisticated impression. It sounds like it's visual impression - great!